Purifying and crystallizing essential oils



UNITED STATES PATENT OFFICE.

CHARLES L. COFFIN, OF DETROIT, MICHIGAN.

PURIFYING AND QFlYSTALLlZING ESSENTIAL OILS.

SPECIFICATION forming part of Letters Patent No. 336,622, dated February 23, 1886.

Application filed November 16, 1885.

To all 11/71/0171., it may concern:

Be it known that I, CHARLES L. GorFIN, of Detroit, in the county of Wayne and State of Michigan, have invented a new and useful Improvement in the Process of Purifying and Orystallizing Essential Oils, of which the following is a specification.

My invention is a process of purifying, concentrating,and crystallizing essential oils; and it consists, broadly, in subjecting an essential oil to the action of an electric current, whereby the empyreumatic products of the prior distillation are oxidized, so that they can be separated by a subsequent distillation at a moderate heat. Essential oils as now obtained by distillation from herbs, &c., contain empyreumatic products, and these products are with difficulty eliminated by redistillation, because of the high heat necessary to rapidly volatilize the essential oil in the still and drive its vapor into the condensing-chamber in advance of the vapors from foreign and deleterious substances mixed therewith, and each distillation results in a loss in the quantity of the essential oil under treatment.

In practicing my invention I subject the essential oil which I desire to purify to the action of an electric current of moderate intensity, which oxidizes the empyreumaticproducts of distillation therein contained, sothat they will not vaporize readily. I then distill the oil at a moderate heat, by which the oxidized products are not vaporized, thus obtaining the oil in a pure state with no appreciable loss.

To facilitate carrying out my process, I take an essential oil and add water to it and form an emulsion by agitating or churning; The churn may be of metal, insulated and included in the circuit of a dynamo. I subject the emulsion so formed to the action of an elec tric current, and the best means of doing this thoroughly with which I am acquainted is to cause the emulsion to flow in a thin sheet over one or more metallic plates, said plate or plates being part of an electric circuit through which an electric current is constantly passing while the operation is going on. This ex- Serial No. 183,021. (No s .ccimens poses all the emulsion thoroughly to the oxidizing action of the electric current. I then take the emulsion, place it in a tight vessel, and force air into the vessel until a moderate pressure is created, when I allow it to stand for some hours until the foreign matters therein contained are precipitated and the oil and water partially separate. During this operation I prefer to continue the action of the electric current by having the vessel insulated and in cluded in an electric circuit. I then draw off the oil and distill it invacuo, during which I prefer to pass an electric current through the still. By this process an essential oil may be purified without appreciable waste, for it is at no time exposed to a sufficient degree of heat to form empyreumatic products, and is freed from such products arising from the first distillation and from foreign matters.

I prefer to use the electric current in all the stages above described herein, but do not wish to be confined thereto, as my invention may be beneficially practiced by using the electric current in one or more of said stages.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is-

1. The process herein described of treating essential oils, consisting in subjecting said oils in a close vessel to air-pressure and the influence of an electric current, as herein set forth.

2. The process herein described of treating essential oils, the same consistingin distilling said oils in cacao, while exposed to the influence of an electric current, as herein set forth.

3. The process herein described of treating essential oils, the same consisting in forming an emulsion of said oils with water, subjecting said emulsion to the influence of an electric current, then subjecting the said emulsion to air-pressure in a close vessel, and finally distilling the same in vacuo, as herein set forth.

CHARLES L. COFFIN.

Vitnesses:

GEO. H. LO'lHROP, SUMNER COLLINS. 

